Abstract 3344

Background:

Major bleeding remains the most frequent adverse effect of oral anticoagulant therapy. A rapid method of reversal is required for patients on warfarin who suffer acute bleeding or require emergency surgery. Octaplex is a prothrombin complex concentrate recently recommended for use by the National Advisory Committee for Blood and Blood Products of Canada (Canadian Blood Services) at a dose of 1000 IU of factor IX activity. It ensures rapid INR correction by providing vitamin K-dependent factors without a large volume load. The main goal of this study was to investigate both the efficacy and safety of Octaplex use in a tertiary care center in Quebec, Canada.

Materials and Methods:

A retrospective review was conducted on the charts of patients who received Octaplex for urgent warfarin reversal between 1 January 2009 and 31 October 2009. Data collected included INRs pre and post Octaplex administration, and documentation of any adverse events.

Results:

We identified 146 occasions when Octaplex was administered for urgent INR reversal. A total of 118 patients were included in the study with a median age of 77. The three most frequent indications for Octaplex were: 1) gastrointestinal bleeding, 2) intracranial hemorrhage, and 3) pre-procedural INR reversal. The majority of patients (90.7%) were treated with Octaplex at a dose of 1000 IU of factor IX activity, with a range of 500 IU to 5000 IU. The average mean pre-and post INRs were 4.00 and 1.65, respectively. Overall, 89.8% (130/146) of patients corrected to an INR < 2.0, of which 51.5% (67/130) corrected to an INR < 1.5. Although 8.2% (12/146) of patients were considered to have a poor response (post INR > 2.1), these patients tended to have a higher mean pre-INR value (5.28 vs. 2.69) and still achieved important absolute drops in INR (range 1.1–9.3, mean 2.91). Only 4 patients (2.7%) did not experience a reversal of their INR. Seventeen patients received second doses of Octaplex, 70.6% (12/17) of whom achieved a post INR < 1.5 and 94.1% (16/17) achieved a post INR < 2.0. There were 8 reported thrombotic events amongst 118 patients: 3 myocardial infarctions, 3 DVTs, 1 ischemic limb and 1 intracardiac clot. All patients with these adverse events had other co-morbities that could have also contributed to these toxicities.

Conclusion:

Octaplex is efficient and appears to be safe in the urgent reversal of INR in patients taking vitamin K antagonists.

Disclosures:

No relevant conflicts of interest to declare.

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Author notes

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Asterisk with author names denotes non-ASH members.